Electronic counter



April 21, 1953 J. B. CAMP 3 Sheets-Sheet 1 F l E- i #Qlii E Z F153. 46 a w 8 w 0 M7 90 O 01 90 C:{M 90 gm 80 f 02 8o 02 8o 02 70 Q 05 70 0} 7o 05 0o 04 @o 04 @o 04 g 2 2 Inventor: JAM/55 5. (AMP,

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April 21, 1953 J. B. CAMP 2,635,809

ELECTRONIC COUNTER Filed Aug. 11, 1950 3 Sheets-Sheet 2 Inventor:

g/ gzi April 21, 1953 J. B. CAMP ELECTRONIC COUNTER 3 Sheets-Sheet 3 Filed Aug. 11, 1950 JQMEj a CZ'MP,

Patented Apr. 21, 1953 ELECTRONIC COUNTER J ames B. Camp, Fairfield, Ala., assignor to United States Steel Corporation, a corporation of New Jersey Application August 11, 1950, Serial No. 178,973

This invention relates to an electronic counter and more particularly to a counter for counting sheets of tin plate as they move along a conveyor. When so counting sheets of tin plate it is necessary to count a predetermined number of sheets to make a bundle. A sheet counter suitable for such purpose is disclosed in my copending application, Serial No. 1,230, filed J anuary 8, 1948, now Patent No. 2,567,422. This counter has proved to be highly successful in use but some of the moving parts therein become worn and have to be replaced from time to time. To the best of my knowledge, other counters in use have not proved to be entirely satisfactory.

It is therefore an object of my invention to provide a counter without mechanical parts which is able to count sheets moving at high and variable speeds.

Another object is to provide such apparatus which has a relatively small number of parts.

These and other objects will be more apparent after referring to the following specification and. attached drawings, in which:

Figure 1 is a schematic view of the counter installed in a sheet classifier;

Figures 2 and 2a, when taken together, disclose a schematic wiring diagram of my invention; and

Figure 3 is a front elevation of the box containing the counter.

Referring more particularly to Figure 1 of the drawings, the reference numeral 2 indicates a conveyor along which the sheets S travel on their way from a shear. At the end of the conveyor 2 is a flap gate 4 which directs the sheets S either to the conveyor 5 which leadsto a mender piler 8 or to the inspection conveyor l!) which leads to a prime piler [2. An electric eye M is located in the path of travel of the sheets .8 to the prime piler [2. As the sheet passes under the electric eye [4 light thereto is cut off and the number of sheets on indicating unit [6 is increased by one in a manner to be described hereinafter. The electrical impulse from the photoelectric cell :4 may be applied to a voltage amplifier l8 which amplifies it to a value sufliciently high to enable it to operate the counter. This impulse varies in shape depending upon the speed at which the sheet passes under the photo electric cell and therefore the pulse from the voltage amplifier I 8 is impressed upon a pulse shaper 20 which, regardless of the shape of the pulse received, will deliver a pulse of uniform shape. This pulse is delivered to an electronic switch 22 which includes two electronic tubes 24 and 26. These tubes are provided with a grid,

4 Claims. (Cl. 235-92) plate and cathode and are of the type in which conduction therethrough is started by means of the bias on the grid and in which conduction is interrupted by removing the plate voltage. D. C. voltage for the counter is applied from any suitable source to lines 28, 30, 32 and 34. The value of the voltage supplied to these lines is determined by means of the voltage dividers 3G, 38 and 40. Lines 28 and 30 have a positive potential, line 32 is at ground potential, the line 34 has a negative potential. Line 28 is connected to plate 24 through resistances 42 and 44 and to plate 281 through resistances 4B and 48. The plates 24F and 26F are connected through a capacitor A negative bias is applied to the grid 24G from the Wire 34 through limiting resistors 52 and 54. A similar negative bias is applied to the grid 25G from the line 34 through limiting resistors 52 and 56. Cathode 2 2C is connected to ground 32. Cathode 25C is con nected to ground 32 through the normally closed contacts 580! of a reset relay 58. The pulse from the pulse shaper 20 is applied to the grids 24G and 26G through a capacitor 6%) which permits passage of the impulse but prevents passage of the direct current.

A bus 62 for a unit indicator circuit 83 is connected to the electronic switch 22 between the resistors 46 and 48. A resistor 64 is located in the bus 52 adjacent the connection to the switch 22. The grid 24G is connected to the bus 62 through a limiting resistor 66 and the normally open contacts 5802 of the relay 58. A bank of neon glow tubes 68-!) to 58-9 are arranged, preferably in a circle, for indicating the units counted. For convenience of illustration the tubes are shown arranged in a line in Figure 2a. Each of the tubes 68 is provided with an anode, cathode and grid. As shown, the tubes have an external grid but tubes with an internal grid can also be used. The tubes are such that a greater potential is required to ionize the tubes than is required to keep them ionized. The bus 52 is connected to the anodes of the even numbered tubes 68-0, 58-2, 68-4, 68-6 and 88-8. A. normally closed contact 5303 is connected in the bus 82 between the anodes of tubes 58-9 and 68-2. A bus in is connected to the electronic switch 22 between resistor 42 and 44. The anodes of the odd numbered tubes 68-5, 68-3, 68-5, 68-1 and 68-9 are connected to the bus 70. A resistor 12 is provided in the bus 10 adjacent the connection to the switch 22. The cathodes of the tubes 68-9 to 68-9 are connected to ground return auto-transformers 14-5 to 14-9, respectively. Any suitable inductor 3 can be used in place of the auto-transformers. l-.e grids of tubes 55I, 3-%-2, fil -3, 58- 5,

li3-5, @5-li, 53-4, t-3, 55-43 and 3-l are connected to auto-transformers lib-5, T l-l, ?2, i i-4%, l l l, i i5, ill-e, i l-4, i i-3 and 'i l9, respectively. One end of each of the auto-transformers 'Mli to I i-e is connected to the ground 32. A selector switch it is provided with ten contacts marked 5 to 9, inclusive, which contacts are connected to auto-transformers. id-ii to 'E 'i9, respectively. The switch I5 has an operating arm is which is connected through resistor to the grid 82G of a gas filled tube 82.

The auto-transformer l l9' also has a tap leading to a voltage amplifier which, in turn connected to an electronic switch 85 which is similar to switch 22. Switch 85 has two: tubes 88 and as of the same type as tubes 24 andzfi. Plate 83F is connected to line 23 through resistors 92 and 94 and plate QQP is connected to line 28 through resistors 2G and 98. The plates 88F and see are connected through a capacitor I 00. The impulse from voltage amplifier 8 3 is con"- nected to grid. 35G through resistor I92 and to grid 92G through resistor Il s. Cathode BBC. is connected to ground 32. Cathode 98C is connected to cathode 250 through line lllfi'whichis connected to ground through normally closed contactcr 53 34. A bus IE2 for a tens indicator circuit I 33 is connected to the electronic switch 86 between the resistors 96 and 98. A resistor H4 is located in the bus adjacent the connection to the switch. The grid 836 is connected to the bus H2 through a limiting resistor I56 and the normally open contcts 586% of the relay 58. A second bank of neon glow tubes 1 i83' to Nil-Q identical with tubes E8@ to 6B9 are arranged preferably in a circle for indicating tens counted; For convenience of illustration the tubes are shown arranged in a line in Figure 2 The bus i I2 is connected to the anodes of the even numbered tubes Ii3@, I!82, II8.4, II8E and liS--8. A normally closed contact 58.05. is connected in the bus 6 iii between the anodes of tubes 2 58-8 and I 58-4. A bus IZil isconnectedto. the switch 85 between resistors 92 andfi i. The anodes of the odd numbered tubes 5 l8-I, i I83, I I3--5 IiS-l, and Il8i are connected to the bus I20. A resistor is provided in the bus l2l3 adjacent the connection to the switch 86. The cathodes of tubes iI8li to tilt-8 are connected to ground return auto-transformers l2l-fi to I2-9, respectively. The grids of tubes I-I8.-I, Ila-2, Ila-I5, IlE- l, tie-55, lit-4, lit-4;. Ila-8, :Ifi9 and il$-il are connected to auto-transformers lfis-l fl t-I, H t-4;, I2. i--3, ilk-4',- i is5, I2 le, m l-3 andIZ L-S, respectively. One end of each of the auto-transformers ifi-fi to -9 is connected to the ground 32'. A selector switch 12% is provided with ten contacts marked to inclusive, which contacts are connected to auto-transforrners IEd-S toI2-i-9 respectively. Switch i225 has an operating arm I28 which is connected through a resistor I353 to the grid ISZG of a gas filled tube I32.

Cathode 326 is connected to line fill. Cathode E3 20 is connected to line 359 and to cathode 82C through a resistor E36. Plate 32F is connected to. cathode I320. Cathode 82C is connected to plate '62? through a switch which is closed only when the arm '58 of switch 75 is on its zero position. The switches 2'3 and I36 may bemounted on a common shaft so that they will operate together in this manner. In like manner cathode i320 is connected to plate I32P'through aswitch 4 I38 which is closed only when arm I28 of switch I26 is on zero position. Switches I26 and I38 may also be mounted on a common shaft so that they will operate together. Plate I32P is connected to wire 28 through the operating coil of a relay Mil. Connected to the wire 28 in parallel with the coil I40. area capacitor I it and a. charging resistor Idfli The: normally open contact M'llCI of relay I40 is connected in series with the coil of relay 58.

I Asecond set of normally open contacts MllCZ may be provided for controlling a light, bell or other equipment- I45 when relay I40 is energized. A normally open reset switch I46 is connected in parallel with the contact I WCI. The capacitor I42 and resistor Hi l are connected to ground through a normally open contact 58C6,

Additional indicator circuits, simila to circuits Mend-I I3 may be provided to indicate hundreds, thousands, etc. An electronic switch is provided for each additional circuit with the parts thereof beingconne'cted to wires 58 and I (36 and to the tap from auto-transformer I2d'9 as indicated by the. arrows. Figure 3 shows a front view of' the indicating. unit I6 in which means are provided for counting. to 999. The tubes in each bank are arranged in a circle and numbered from B to 9 as shown. The pointers I8 and I28 as well as the pointer for the hundreds unit are arranged on a numbered dialwith the preset number appearing through windows I 58 in the wallof'indicating unit IS.

The operation of the device is asfollows:

Assuming. that direct. current is being applied to thesystem as shown,.there will'be sufiicient negative bias. from the line 34 on the grid 24G and ZSGto preventthe. tubes 214 and 2.6 fromconducting. To prepare the system for counting, the reset switch. I46 is closed, thus energizing the coil of relay 58. This momentarily opens contact 580! thus. preventing flow of current through the tube 26 and at the sametime closes contact 58(32 which will decrease the negativebias onv grids 25G andlIiG. to.a point sufiicient tostart tube. 24 conducting. Tube 26 cannot conduct. because. its cathode circuit isopen. Since tube 26-is not conducting, sufllcient potential. is. supplied to bus 62 to cause the tubes 68 to conduct. However, contact 58(33 ofrelay 58 will also be open so that the initial potential on bus 62 isonly applicable to tube=68--0. As soon. as this. tube starts conducting therewill be. a voltage drop acrossv resistor 64 which reduces. the voltage at the anode of the even numberedtubes to a value sufiicient to ma tain ionization, but not suificient. to cause ionization. Therefore; when relay 5.5 is-deenergized and contact: 58GB: closes, the. other even numbered tubes cannotiionize but the. zero tube will remain light. Inlike manner. only zero tubes are made light in all other banks. When tube 24 isconducting, its plate voltageris les than the voltage on plate 26? because of the drop in potential through resistors 42 and: M. Therefore, capacitor 5D- is. charged with a potential having the polarity shown inFigure-2'. Also, when tube 24 isconducting, it draws current through resistor 42' andreduces thepotential' on the bus 'II! and therefore the potential on the anodes of the odd numbered. tubes to a point below that necessary to sustainionization. Whenthe first sheet S passes under the: photoelectric cell I4 a positive charge is. impressed on the grids ZQG and 26G through the capacitor Eli. This'red'uces the negative bias on grid. ZBG-toa point where tube 28' will start conducting. When this happen the potential on plate '26P willdecrcase because of current flowing through resistors 46 and 48 until the potential is equal to that on plate 24?. The capacitor 50 will then discharge electrons from the negative to the positive side in order to neutralize the charge. This flow of electrons causes a voltage drop across resistor 42 and 44 which reduces the potential of plate 24P sufficiently to stop tube 24 from conducting. When this occurs, the capacitor 56 will recharge with a polarity opposite to that shown. When tube 26 conducts it draws current through resistance 46 to reduce the potential on bus 62 to a point below that necessary to sustain ionization of the even numbered tubes. Since tube 24 is not conducting, the voltage on bus 1!! is sunicient to sustain ionization of the odd numbered tubes. Tube 68-8 will be deionized and will stop drawing current through the auto-transformer 14. This induces a large voltage in the winding of the transformer of such polarity as to oppose the change in current. This voltage is applied to the grid of tube 6S-i and in combination with the sudden increased anode voltage will cause tube 68-I.to ionize. Tube 68-I will draw enough current through resistor l2 to reduce the voltage available at its anode to a value sufficient to sustain ionization, but insufficient to cause ionization so that none of the other odd numbered tubes will ionize. While all of the odd numbered tubes had the same anode potential as tube G8I only tube 68-1 received the inductive kick on its grid which permitted it to ionize before the other odd numbered tubes had an opportunity to do so. Once tube 63-I ionizes it draws enough current through resistor I2 to prevent the other odd numbered tubes from ionizing. When a second sheet S passes under the electric eye I4, conduction is switched back to tube 24 by reducing the potential on grid 24G to cause the tube 24 to fire, which in turn, causes the capacitor 53 to stop tube from firing. When tube 24 fires the potential on the anodes of the odd numbered tubes is reduced to a point where they cannot remain ionized. When tube 68-I deionizes it gives an inductive kick to the grid of tube 68 2. This causes tube 68-2 to ionize immediately, thus drawing current through resistor 64 and dropping the potential on the anodes of the even numbered tubes to a value insufiicient to cause ionization of any of the other even numbered tubes. This operation repeats itself until tube GIL-9 is ionized.

When the tenth sheet S passes under the photoelectric tube I4, tube 53-3 will ionize due to the inductive kick from auto-transformer I4-9. Voltage from transformer 'I4-9 will also be fed to amplifier 84 where it is amplified and inverted and used to trigger electronic switch 86. This causes tube II8--I to ionize in the same manner as explained above. When the twentieth sheet passes under the photoelectric eye I 4 another pulse from auto-transformer 14-4! is impressed on switch 86, thus deionizing tube I I3-i and ionizing tube I I8-2.

If desired, an additional bank of neon tubes identical with the units and tens banks may be provided by connecting the line I66 to the cathode of a tube similar to tube 98 of an electronic switch (similar to switches 22 and B5) and by connecting a tap from the auto-transformer I 24-9 to a voltage amplifier similar to amplifier 84. Each addiiional bank will work in the same manner as the tens bank.

In some instances, such as in counting sheets of tin plate to make a bundle, it is desired to return the counter to zero after a predetermined number of sheets have been counted. Assuming that sixty-six sheets are to be counted, the pointer I8 will be placed on contact 6 of the switch I6 and the pointer I28 will be placed on contact 6 of the switch I26. When the sixth sheet is counted, a positive pulse is applied across ground return auto-transformer 'I45. This pulse is applied to the grid 82G. However, tube 82 will not conduct since it does not have any plate potential until tube I32 conducts. When the sixtieth sheet is counted, a pulse is applied to grid I32G and since there is potential on plate I32P, tube I32 will conduct. However, its cathode return is through resistor I34 which has a high resistance so that it limits the plate potential of tube I32. As a result, tube I32 will not draw enough current to energize the coil of relay I4Il. When the sixty-sixth sheet is counted, a pulse is applied to grid 82G and since there is potential on plate 821?, tube 82 will start conducting. The cathode return of tube I32 will then have a very low impedance path through tube 82 to the ground and the conduction through tube I 32 will be suflicient to cause the coil of relay I40 to energize. Energization of relay I40 closes contact I40CI, thus energizing the coil of relay 58, which in turn, resets the counter to zero. At the same time, contact I4IJC2 closes, thus turning on a light, sounding a bell or performing other actions. Energization of relay 58 closes contact 5806 so that the previously positive left side of capacitor I42 will be at ground potential and the capacitor I42 will be recharged to a new value with opposite polarity. The recharging action will cause a voltage drop of such polarity as to reduce the plate potential of tube I32 below the value necessary to sustain ionization, thus cutting oil tubes I32 and 82. If nine or less objects are to be counted, the switch 933 will be closed since the pointer I28 is on zero. In this case the tube I32 will be by-passed and tube 82 will be energized the first time that a pulse is applied to its grid. In like manner, if the pointer I 28 is set to zero, switch I36 will be closed and the coil of relay I40 will be energized as soon as tube I 32 conducts.

For each additional bank of neon tubes, additional gas filled tubes similar to tubes I32 and 82 are inserted between tubes 82 and I32 with a high resistor similar to resistor I 34 inserted in the cathode circuit,

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. Apparatus for counting moving objects comprising a group of glow tubes, each of said tubes having a grid, anode and cathode, an electronic switch, means actuated by each of said moving objects for supplying an electrical impulse to said electronic switch, a first bus connected to said electronic switch, a second bus connected to said electronic switch, current being supplied to one of said buses by alternate impulses and to the other of said buses by the remaining impulses, connections between the first bus and a first electrode of alternate glow tubes, connections between the second bus and a first electrode of the remaining glow tubes, the first electrodes in both of said connections being of the same polarity, a resistor in the first of said buses adjacent its connections to the electronic switch, a normally closed contact in said first bus between the first and second connections from 2,835, SUE) 7 said first bus to said tubes, said contact: being momentarily opened when the counter is started in operation, an inductor for each of said glow tubes normally connected to ground, a tap between each of said inductors and the second electrode of its adjacent glow tube, and a tap between each of said inductors and the grid of the next succeeding glow tube, the last named tap from the last of said inductors being connected to the grid of the first of the group of glow tubes.

2. Apparatus for counting moving objects according to claim 1 including a second group of glow tubes similar to the tubes of the first group, a second electronic switch, a tap connecting the last inductor or" the first group of glow tubes to the second electronic switch, a third bus con.- nected to the second electronic switch, a fourth bus connected to the second electronic switch, connections between the third bus and an electrode of alternate glow tubes of the second group, connections between the fourth bus and an electrode oi the remaining glow tubes of the second group, a resistor in each ofsaid third and fourth buses adjacent their connections to the second electronic switch, a normally closed contact in said third bus between the first and second connections, said contact being momentarily opened when the counter is started in operation, an inductor for each of said glow tubes of the second group connected to ground, a tap between each of said last named inductors and the other electrode of its adjacent glow tube, and a tap between each or" said last named inductors and the grid of the next succeeding glow tube, the last named tap from the last of said inductors being connected to the grid of the first of thesecond group of glow tubes.

3. Apparatus for counting a predetermined number of objects comprising a group of glow tubes, each of said tubes having a grid, anode and cathode, an electronic switch, means actuated by each of said moving objects for supplying an electrical impulse to said electronic switch, a first bus connected to said electronic switch, a second bus connected to. said electronic switch, current being supplied to one of said buses by alternate impulses and to the other of said buses by the remaining impulses, connections between the first bus and a first electrode of alternate glow tubes, connections between the second bus and a first electrode of the remainin glow tubes,

the first electrodes in both of said connections being of the same polarity, a resistor in the first of said buses adjacent its connections to the electronic switch, a normally closed contact in said first bus between the first and second connections from said first bus to said tubes, said contact being momentarily opened when the counter is started in operation, an inductor for each of said glow tubes normally connected to ground, a tap between each of said inductors and the second electrode of its adjacent glow tube, a tap between each of said inductors and the grid of the next succeeding glow tube, the last named tap from the last of said inductors being connected to the grid of the first of the group of glow tubes, a second group of glow tubes similar to the tubes or the first group, a second electronic switch, a tap connecting the last inductor of the first group of glow tubes" to the second electronic switch, a third bus connected to the second electronic switch, a fourth bus connected to the second electronic switch, connections between the third bus and an electrode of alternate glow tubes of the second group, connections between the fourth bus and an electrode of the remaining glow tubes of the second group, a resistor in each of said third and fourth buses adjacent their connections to the second electronic switch, a normally closed contact in said third bus between the first and second connections, said contact being momentarily opened when the counter is started in operation, an inductor for each of said glow tubes of the second group connected to ground, a tap between each of said last named inductors and the other electrode of. its adjacent glow tube, a tap between each of said last named inductors and the grid of the next succeeding glow tube, the last named tap from the last of said inductors being connected to the grid of the first of the second group of glow tubes, a pair of selector switches one for each of said groups of glow tubes, each of said switches including an operatin arm and a plurality of contacts equal in number to the tubes in the associated group, a tap connecting each of said contacts to one of said inductors, each of said operating arms being positioned on one' of its associated contacts, a relay coil for operating said normally open contacts, means for energizing said relay coil when the predeter mined number of objects are counted, and means connecting said operating arms to said last named means.

4. Apparatus for counting a predetermined number of objects comprising a group of glow tubes, each of said tubes having a grid, anode and cathode, an electronic switch, means actuated by'each of said moving objects for supplying an electrical impulse to said electronic switch, a first bus connected to said electronic switch, a second bus'connected to said electronic switch, connections between the first bus and an electrode of alternate glow tubes, connections between the second bus and an electrode of the remaining glow tubes, a resistor in each of said buses adjacent their connections to the electronic switch, a normally closed contact in said first bus between the first and second connections, said contact being momentarily opened when the counter is started in operation, an inductor for each of said glow tubes connected to ground", a tap'between each of: said inductors and the other electrode of its adjacent glow tube, a tap between each of said inductors and the grid of the next succeeding glow tube, the last named tap fromthe last of said inductors being connected to the grid of the first of the group of glow tubes, a secondigroup of glow tubes similar to the: tubes of the first group, a second electronic switch, a tapconnecting the last inductor of the first group of glow tubes to the second electronic switch, a third bus connected to the second electronic switch, a fourth bus connected to the second electronic switch, connections between the third bus and an electrode of alternate glow tubes of the second group, connections between the fourth. bus and an electrode of the remaining glow tubes of the second group, a resistor in each of said third and fourth buses adjacent their connections to the second electronic switch, a normally closed contact in said third bus between the first and second connections, said contact being momentarily opened when the counter is started in operation, an inductor for each of said glow tubes of the second group connected to ground, a tap between each of said last named inductors and the other electrode of its adjacent glow tube, a tap between each of said last named inductors and the grid of the next succeeding glow tube, the last named tap from the last of said inductors being connected to the grid of the first of the second group of glow tubes, a pair of selector switches one for each of said groups of glow tubes, each of said switches including an operating arm and a plurality of contacts equal in number to the tubes in the associated group, a tap connecting each of said contacts to one of said inductors, each of said operating arms being, positioned on one of its associated contacts, a relay coil for operating said normally open contacts, a pair of tubes each having a cathode, grid and plate, a conbetween the grid of the first of said pair of tubes and the operating arm of the selector switch for the first group of glow tubes, a connection between the grid of the second of said pair of tubes and the operating arm of the selector switch for the second group of glow tubes, a connection between the plate of the first tube and the cathode of the second tube, a connec tion between the plate and cathode of the first tube, a switch in said last named connections, said last named switch being closed only when the arm of the first selector switch is on zero, a connection between the cathodes of said tubes, a

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,519,184 Grosdoff Aug. 15, 1950 FOREIGN PATENTS Number Country Date 436,420 Great Britain r Oct. 10, 1935 OTHER REFERENCES Electrical Counting, W. B. Lewis, Cambridge, 1948, page 65. 

